Metal milling machine



Dec. 6, 1932. R, J; MCLEQD 1,890,399

METAL MILLING MACHINE Filed Nov. 29., 1930' v 5 Sheets-Sheet l Dec. 6, 1932,

R. J. MCLEOD METAL MILLING MACHINE Filed Nov. 29. 1950 5 Sheets-Sheet 2 1203er; www;

De`c. 6, 1932. R. J. McLEoD 1,890,399

METAL MILLING MACHINE Filed Nov. 29, 1930 5 sheets-Sheet 5 'Patented Dec. 6, 1932` f METALLMILLING applicati@ meh november 29, 193e,V serial No, 499,o74ana.4in eaffizntainglneeenter ''Qiae Thisl inventionfrelates' to machines, such asthread cutting machines, using milling cutters or hcbs,'in which the tool and the work normally rotate atv constant speeds, lbut `at certain stages ofthe operationth'e' relative velocity'of the tool and Work is' varied by suitalolev gearing and a corresponding'riela-V tive longitudinal traverse .imparted to the tool relatively tothe Work,

r In such machines it 1s sometimes desirable t to, have apredetermined'starting pointonfthe circumerencefand also on the axialflength of the Workffor the purpose` of forming ascrew: thread, sc1foll,^gear toot h or shaped contour sojthat each succeedingproduct isexactly Y alike in' this respect( `v`Bpllany instances'poccnr Where such a condition is of great advantage,

in particular 'Where in tvvo parts to be screwed'` together, it is'necessaryffor the male `and female parts, when assembledft'o be in ce`r` tain definite .relative 'positions,lor Where it is desiredto milla continuation of an existingV thread, as in fthe, case of doubleV tapered socket'svfor pipe lines.' In gears it is someti'mes necessary for tlie'teeth to be a definite relationship to a crank, cam or` other device,-

as lc alculating machines, totalizlators, 'timing devices andthe like.

The present invention v'consists 'inmeans for automatically restoring the tool to a pre# determined axial Vvand angular position relatively to the Work. W i l l In my"speciiication Serial No.` 309,777, I

have described' a thread millingma'chine for,4

VInfthe present invention, in which' a similar v differential vrmechanism and .means for? op-Y erating the leadV screw are employed, the hol)` or cutter ma vhave an'f redetermined s eed Y `y 4 l) kof rotation relative to th at of the Work'.

' To fulfill the conditions required it is n'ecesf y sary for the critters to commence the cut at;

i parti-@una point? "onf the leona i l,

'-rested. L

peri'pheryand alsoto the axial length ofthe Work, to enable. thecutting action'tol `heifer-'V i peated pieces.`

nafta@ fcfase"arborA of,'gewremat s also "f necessary that fa' f' definite ,"point'fon, the j Y peripheryfofjthe jli'ob .should coincid d ,'lfofcar'ryl out this Y invention',`jI provide an automatic reverse motion, L`vvl`1e1`ceby, aftergtheV Work completedorlpartiallyffinished,by fwithamwiguiefhab andas Saddle-clearer Y y `the Work, acliitchis,engaged'ivhichbrings f' the reversing` 'gear,`into action, reversing-the l5 f1.

differential gear` andalso' the leadQscrevv.` .Y

The reversal fof motion' of @the dierential gear and leadscrevv vyillr'estore'themtotheir respective "original "positions, fthe hob, saddle may have vbeen decoupled from the leadscrew.; .W'hen, therefore, any" are and all urther'pmotion arrested.

fr@ eat-acteurs @1e-clutching and arresti, Iisi Vrestored to 'their'l original,positidns,1V there# vverse `motion Inustfbeinstantly declntche'd i range a cam orY cylinder littedwith adjustable i stops; which engage 'With'a lever operating.

a tripl device v`fordisengaging Jthe lclu'tch.

movement@ are differ@naall gear, alla lead.

screw 'is alsoarrestedlwith the Work spindle, whilst the reverse"moi,V

of thescam or lvvillloe arl".

r The eb' of.'cuaerfwili,coniinuefgratafef tionis inaction, with theac'celeration or rel @maande f @dienaar When`fthe hob isrestored toits originalposi- 'tion and' the Q reverse m'otionfarested, every point on the hoh willfhaye itslcounterpartvon the circumference.ofrthevvorli exactly aspny the original pieceOfwork.

originalzpositionfif thel ysfa'dcll'e iskslid 1 to an adjustable deads't'o'p, 'setto niarkthe' tudinal traverse to the'hub 2l in dependence`-r to the hob by the differential mechanism 15 ,i

ment of the arm 64 as it rides up the inclined surfaces of the teeth.

Inv Fig. 4, a cam disc 69 replaces the grooved i cylinder 46.` A lpin 70 on the sliding bar 49 engages ina suitably shaped groove V"(1 in the 1 Cylinder 7 4, effects the required longitudinal movements of thefbargf' The action of the machine is 'as ed, the thread having been already formed on the inner portion adjacentto the chuck, and that the thread on the outer portion mustbe a continuation of the vexisting thread.

The gear ratios are' set to impart a longion theacceleration orlretardation imparted the longitudinal slideQ is traversed by hand until the hob is in position to continue the thread already formed. The stop 50 isset to this position anda stopV 75 ion the slide limits vthe movement in thisdirection. 7

In this position' the differential gear is disconnected fromfthe tool .and thel lead screw,

and the tool 'andworkcan berotated from the' shaft 10 at therequired-speeds andthe'cutting effected at Work.

Whenit is `desired to bring into operationy tool to' move said clutchinto the neutral posithe differential movement and the `relative traverse, the handlever 55 is pulled over to' engage'the clutch 31- in the desired direction, f

so that, for example, the V pinion 29 is ingear With the Wheel 32, andthe cylinder 46 rotates i a Vwhich the tool and the Work-normally rotate fi 1 in the. direction to move the dog 48 and bar 49 to the right until the stop engages with the lug 52 and brings the clutch 31 intov the disengaged position in which thefdiiferential mechanism and traversing gear are out ofV action. The tool and Work are now rotating at Yce into the disengaged position;

the original speeds, but'no acceleration or reif at the commencement of the operation a centre line were drawn through the housing 22 and a second line parallel toV the former from a point on the. periphery ofthe hob,'a t the end of each'reversal these lines would be 'Y forv repetition 'follows z-f Y It isassumed that the outer portion ofthe f double tapered socket 6 is to be screWthread-' the required, position of the,

in the same relative positions and the-1` cuts` ting operations `canbe v'repeated with :the requiredgaccuracy. 7

, VTjhe inventlon'c'anfbe vused with 'any1` forni'7 of hob ormilling cutter and lis adaptedeitherff ork ory for repeating thercu't on the Same Work. Y

I-claim`zV .lMf *ff f x 1.,Ina machine for elfectingmilling operi ations, such as thread'cutting by'chobs, in

` which the tool and the Worlnormally rotate at constant speeds, but atcertain stages of the operation the relative velocity of the tool' andl Workis varied byvsuitable gearing anda cor-1;

responding longitudinal traverse is imparted to the tool, means, for the purpose described,

for automatically restoring the tool toa pre-V determinedaXial and angular position' relatively to the Work, a saddle on which the' tool is mounted, differential mechanism by which the speed' orgrotation of the tool can be ad`- justed relatively. to that ofthe Work, a. slidf ing clutch andgears connectibleto said clutch for operating said differential mechanism and saidtraverSing movements of the saddle, thev lsaidlclutch havingva centralneutral position and two end positions forrotating said differential mechanism, respectively, i'n Aopposite t directions, a cylinder rotated bythe gearing' t operating said differential mechanism, ini cline'd surfaces on saidv cylinder,l afslidable rod, a member secured vt'o saidrod and 'engag f ing .With saidinclined surfaces, stops onjsaid' rod, -a second slidable vrod connected to said clutch anda lug thereon adaptedto engage Withsaid stops in the'limiting positions of the I tionvvhen the toolis at'either of its limiting positions.` f

v2.-`In a machine for effecting milling operations, such, as thread cutting by' hobs, in

at constant speeds, but at certain stages ofthe Work is varied suitable gearing and a cor-` tively tothe Work, asaddle on which the tool thespeedv of, rotation of" the tool can bead- Y justed relativelyto that of the Work,a` sliding` i' clutch' and gears connect-ible to said clutch for operating said differential mechanism'and"120 saidu traversingfmovements'-of the saddle, thev said clutchhavingja "central neutralposition f and tWoend positionsforrotating saiddiffer;` f entialmechanism, respectively, in opposite i "f f directions, cylinder rotatedbythe gearing operating said ydifferential'mechanisnn1n' clined grooves onsaid cylinder ,aslidablerod, 4 i

a dog secured to said rod and Vengaging Withf saidinclined grooves,fstops on saidrod,a. sec-,

\ ond slidable rod connected tosaid clutch'and-fia i i v119mm@ kcci this specication. v A

" imY Whefe'of ROBERT n JAMES MGLQD. .x 

